Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
This invention relates to shot blasting
machin~ry and it is an object of the present
invention to provide a shot blasting machine of
versatile and variable construction.
According to one aspect of the present
invention there is provided a shot blasting
module adapted for communicating assembly with
a blast cabinet modula, the shot blasting module
comprising a casing hou~ing at least one abrasive
throwing wheel assembly, an abrasive/contaminant
separator, and a two-stage vertical conveyor
mean~ adapted simultaneously to direct spent abrasive
and contaminants delivered from the blast cabinet
module into the ~hot blasting module into the
separator, and to dsliver clean abrasive into
a storage hopper from which it is directed to the
throwing wheel assemblyO
Preferably the or each throwing wheel assembly
is mounted on a swing-out door of the ca~ing ~hich
facilitates maintenance and avoids the need to
provide an externally mounted hood within which
such throwing wheel aissemblies are conventionally
housed as is well known to those skilled in the
art
In a modification, the or each wheel assembly
is mounted on a wall' of the casing, at least one
door being provided for access. H~re again, no
hood ie required.
Q
The delivery of abrasive from the storage
assembly
hopper to the or each throwing whcel/is preferably
v a control valve. lf there is more than one
control valve ~i.e. more than one throwing ~h-eel
assembly) thsn the valves are preferably independently
operable.
Preferably, the thro~ing ~heel assembly,
in use, is housed in a wear-resistant lined compartment
ofthe modula casing. The compartment i~ formed of,
or lined with, mangane~e for exampls.
The conveyor means praferably comprises an
endless bslt carrying two parallel rows oF buckets,
which belt is driven at the top by a geared motor,
preferably fitted ~ith an anti-run back device.
The fact that the elevator motor is the only
motor additional to the throwing wheel assembly motor
or motors in the shot blasting module render~ the
machine a low energy user.
There is thus provided a shot blasting module
which, when compared with known ~hot blasting
machinsry, is self-contained, i.e. all ths operative
components are hous~d within the caAing, and is of
lesser height, due to the provi~ion of the two-stags
conveyor, thus permitting its installation in
locations of restricted headroom.
The blast cabinet module may be of any convenient
construction in~cluding, inter alia, a swing table,
a haoger arrangement, a continuous conveyor, and an
endle~s in-out conveyor.
According to a second aspect of the present
invention there is provided a shot blasting machine
comprising, in combination, a blast cabinet module
and a shot blasting module as hereinbefors defined
in the preceding paragraphs.
Preferably the machine also comprises, in
combination, a dust collector module.
It will be manifest that the number and
arrangement of modules constituting the shot
blasting machine can be varied to suit a customer~s
particular requirements.
An embodiment of the pre~ent invention will
now be describsd, by way of example, with reference
to the accompanying drawings, in which:-
Fig. 1 is a front elevation of a modular shot
blasting machine according to the invention;
Fig. 2 is a corresponding end elevation;
Fig. 3 is a cGrre~ponding plan view;
Fig. 4 i9 a view showing a typical blast
pattsrn for a given machine;
Fig. 5 is a fragmentary side elsvation anddstail
view of the shot blasting module;
Fig. 6 is a diagrammatic perspective view
of the ~hot blasting module; and
Fig. 7 i9 a schematic flow diagram showing
clean and dirty abrasive paths through the machine.
The shot blasting machine comprise~ a blast
cabinet module 10, a shot blasting module 11 and a
dust collector module 12, all assembled togsther in
~gl~
the di~position shown and with the shot blasting
module 11 in communication with the blast cabinet
modul~ 10 ~hich i~, in turn, in communication with
the du~t collector module 12.
The bla~t cabinet module 10 is directly connected
to the ahot blasting modula 11, i.e. no intervening
ductwork, but i~ connected to the dust collector
module 12 through the intermsdiary of a manifold 9pi-
-got 13 ~hich facilitates connection and which makes
re-3iting it relative to the blast cabinet module
1û easier.
~n thi~ embodimsnt, the bla~t cabinet module
10 include~, for the workpiece ~, a hanger 14
rotatable by a ~eared motor 15 to enqure that all
surfaces of the ~orkpiece W are pre~ented to the
cleaning ~traam of abrasive emanating from the ~hot
bla~ting module 11.
The blast cabinet module 10 ha~ a hinged ~ork
acces~ door 16 projecting outwards from the front of
the module to provide ease of access to the ~orkpiece
W.
The blast cabin~t module 10 is of pitless
design as can be seen, it has, as i~ cu~tomary, on
its inner wall surfaces ea~ily replaceable hook-on
~ear tiles ~not ~hown). A scre~ conveyor 17 returns
spent, i.e. re-u~a~le, abrasive and contaminants
to the boot 1B of the shot blasting module 11.
The blast cabinet module 10 has a perforated
floor plate 19 dispo~ed above the ~cre~ conveyor
17 to ensure that large pieces of contaminant are
retained in the blast cabinet module 10 for eventual
removal.
An adju~table metering or surgB plate (not
shown) is arranged below the perforated floor plate
19 and above the ~crBw conveyor 17 to ensure that the
screw conveyor is not flooded with spent abrasive
and contaminants thereoy avoiding hlockage of the
screw conveyor.
The dust collector module 12 has a top mounted
dust exhaust fan 20 driven by a motor 21. It i3,
for exampls, a continuously-opsrating filter unit and
the exhaust fan 20 provides a constant rate of air
extraction volume from the blast cabinet module 10.
The dust collector module 12 contains filter
element~ and has a silencer on ths exhaust fan 20,
nsither of these components being shown.
Air from the du~t collector module 12 i~
returned back to the ~orkshop as can readily bs
~een which eliminates lo9Y of heat to atmosphere
thus giving con~iderable saving3 in workshop heating
costs~ `
The dust collec~or module 12 embodies an
automatic cleaning syqtem ~ell-known in the art and
which cau~es du~t to fall into a dust collecting
trolley 22 which can be withdrawn from the dust
collector module 12~ for dust di~po~al. Alternative
~ithdrawal locat`ion~ are indicsted in Fig. 3.
An acce~s door to the dust collector module
12 is indicated at 23.
3~
R~f9renCe i5 now made to the shot bla~ting
module 11 which, as aforesaid, is in direct
communication, i.e. no intervening ductwork with
the blast cabinet module 10.
Thi~ ~hot blasting module 10 compri~es a ca3ing
24 defining a compartmont which i~ normally manganese
lined and houses two vertically-~paced rever~ible
thro~ing ~heel a~eemblie~ 25 such, for example, as are
disclosed in our United Kingdom Patent No.1 500 092.
Each throwing wheel as~embly 25 is, a~ can be ~een in
Fig. 5, hoodless and is driven by a low-noisa, direct-
coupled, flange-mounted, totally enclosed motor 26.
Each throwing wheel assembly 25 and it~ motor 26
is mounted on a ~wing-out door 27 for ease of access.
The baqic conRtruction of such abra~ive thro~ing
~heel assemblies are very well known to those ~killed
in the art and ~ill not there~ore be described in
detail. The throwing wheel i9 indicated by refersnce
28 and it~ abra~ive delivery ~pout by reference 29.
The ~pout 29 is secured to the door 27 by a brackst 30.
Each door opening is provided ~ith an apertured
rubber ~ealing plate~31 through ~hich the thro~ing
~heel assembly 25 pa~ses and into ~hich a flange of
the motor 26 engages to provide an anti-vibration
feature and ~ealing again~t abrasive egress from the
manganese-lined compartment.
The thro~i~g wheel as~emblie~ 25 incorporate
anti-vibration mounting~ and their motors 26 have
heavy duty shafta and bearings and are thyri~tur
protected.
)3~
8.
The shot blasting module 11 also incorporates
an elsvator mean~ ano a 3sparator.
The elevator means is an endless belt conveyor
32 carrying two parallel rows of lifting buckets
and is
A and ~/drivèn at its top by a totally enclo~ed geared
motor 33 which reduces noi~e levels.
The conveyor 32 can handle both clean and
spent abra~ive ~imultaneously while keeping both
separate as can clearly be seen from Fig~. 6 and 7.
The conveyor 32 is fitted with a run back
prevention locking device (not shown).
~he conveyor 32 is fitted with sealed-for-life
bearing~ and is provided with a floor level screw
tensioning arrangement ~not shown~.
The conveyor 32 has two parallel and separate
rows of buckets designated, a~ aforesaid, A and B.
Bucket row A serves (see Figs. 6 and 7) to raise spsnt
abrasive and contaminant~ from the boot 18 of the
shot blasting module 11 and deliver same by gravity
to a separator 34 ~om which clean abrasive is returned
to the boot 18. Separation of contaminants from the
abrasive is effected'by passing an air stream through
ths falling abra~ive. As th~ abrasive falls through
the ~eparator 34 by gravity the only power required
in operation of the separator is that needed to
generate the air fldw which, of course contributes
to the overall energy sconomy of the machine. A
sieve 35, which may be removable, is dispo~ed below
this air wash separator 34 for final cleaning prior
3(;~
to the cleaned abrasive passing into the boot 18.
The bucket row B conveys clean abrasive to a storage
hopper 36 from which abrasive is fed v~a a control
valve 37 and a pipe 38 to the feed spout 29 of
S each of the throwing wheel assemblies 25.
It is to be noted from Fig. 5 that ~han the door
27 is closed the opening into the feed spout 29 lies
directly below the delivery pipe 38. Manifestly,
the delivery pipe 38 for the upper throwing wheel
assembly 25 is shorter than that for the lower
throwing wheel assembly 25.
To ensure no (or very little) inter~ingling
of the spent abrasive and contaminants and the
clean abrasive, there is provided at the upper end
of the conveyor 32 a T-shaped splitter plate 39
with two openings 39A and 39~ ssparated by the stem of the
T, the clean abrasive falling through opening 39A
to one side of this splitter plate 39 for guidance
into the storage hopper 36 while the spent abrasive
and contaminants fall through the opening 39B tu the
other side of the splitter plate 39 and are guided
by plates 40 and 41 into the air wash separator 34.
A window is located at locatinn 42 to permit
inspection of the abrasive level i.n the storage hopper
36.
A build-up of abrasive indicated at 43 occurs
below the sieve 35 to provide an inclined abrasive
surface which i9 contacted by abrasive passing through
1 0 .
the air wa~sh prior to its return to the boot 18.
This assists in reducing wear.
There is provision at 44 for extraction of
hsavy du~t from the separator 34, and debri~ from the
boot 18 can be extracted at 45.
Access to the separator ~4 is via door 46.
The separator 34 may incorporate a vioratory
sieve deck.
The control valves 37 are both pneumatically
controlled and sound-proofed, and they open and close
independently. They may be otherwise controlled
including being hand-operated.
When the motors 26 are shut off, the elevator
32 is allowed to run for a short time with valves
37 open to allow abrasive to be continued to be fed
to the throwing wheel assemblias 25. This flooding
of the throwing wheel assemblies 25 with abrasive
serves to brake them 50 reducing run-down time.
Constant exhaust air volumes from the separator
and the blast cabinet ensure a balanced non-surge
arrangement within the machine.
The control pane~ 47 for the machine is
contained within the shot blasting module as shown.
All door~ have double labyrinth or other
convenient seals.
The blast cabi?et module can be other than that
described, for example it may be of the fixed table
type, the ~wing table type, T-track type for continuous
throughput of workpieces, or roller conveyor type for
3()
1 1 .
handling heavier or bulkier ~orkpieces. All of these
are well-kno~n to those skilled in the art.
